MCQ Questions for Class 11 Chemistry Chapter 7 – Equilibrium With Answers

MCQ Questions for Class 11 Chemistry Chapter 7 – Equilibrium With Answers

1. A reversible reaction is one which
(a)  Proceeds in one direction
(b)  Proceeds in both directions
(c)  Proceeds spontaneously
(d)  All the statements are wrong
Ans 1. (b)

2. Which of the following is a characteristic of a reversible reaction
(a)  Number of moles of reactants and products are equal
(b)  It can be influenced by a catalyst
(c)  It can never proceed to completion
(d)  None of the above
Ans 2. (c)

3. In a reversible reaction both side rates of reactions are
(a)  Same
(b)  Different
(c)  One side more
(d)  Not definite
Ans 3. (a)

4. Which of the following reactions is reversible
(a)  H₂ + I₂ → 2HI
(b)  H₂SO₄ + Ba(OH)₂ → BaSO₄ + 2H₂O
(c)  NaCl + AgNO₃ → NaNO₃ + AgCl
(d)  Fe + S → FeS
Ans 4. (a)

5. Which one is a reversible process
(a)  Melting of ice at 10 ⁰C
(b)  Mixing of two gases by diffusion
(c)  Evaporation of water at 100 ⁰C and 1 atm pressure
(d)  None of these
Ans 5. (c)

6. All reactions which have chemical disintegration
(a)  Is reversible
(b)  Is reversible and endothermic
(c)  Is exothermic
(d)  Is reversible or irreversible and endothermic or exothermic
Ans 6. (d)

7. Amongst the following chemical reactions the irreversible reaction is
(a)  H₂ + I₂ → 2HI
(b)  AgNO₃ + NaCl → AgCl + NaNO₃
(c)  CaCO₃ → CaO + CO₂
(d)  O₂ + 2SO₂ → 2SO₃
Ans 7. (b)

8. The reaction, 3 Fe (s) + 4H₂O ⇌ Fe₃O₄ (s) + 4 H₂ is reversible if it carried out
(a)  At constant pressure
(b)  At constant temperature
(c)  In an open vessel
(d)  In a closed vessel
Ans 8. (d)

9. Amongst the following chemical reactions the reversible reaction is
(a)  FeCl₃ + 3H₂O → Fe(OH)₃ + 6HCl
(b)  NaCl + H₂SO₄ → NaHSO₄ + HCl
(c)  (a) and (b) both
(d)  None of these
Ans 9. (a)

10. Which of the following conditions represents an equilibrium
(a)  Freezing of ice in an open vessel, the temperature of ice is constant
(b)  Few drops of water is present along with the air in a balloon, the temperature of the balloon is constant
(c)  Water is boiling in an open vessel over a stove, the temperature of the water is constant
(d)  All the statements (a), (b), and (c) are correct for the equilibrium
Ans 10. (b)

11. Chemical equilibrium is dynamic in nature because
(a)  Equilibrium is maintained rapidly
(b)  The concentration of reactants and products become the same at equilibrium
(c)  The concentration of reactants and products are constant but different
(d)  Both forward and backward reactions occur at all times with the same speed as
Ans 11. (c)

12. One dm³ of 2M ethanoic acid is mixed with one dm³ of 3M ethanol to form an ester, CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O. The decrease in the initial rate if each solution is diluted with an equal volume of water would be
(a)  2 times
(b)  4 times
(c)  0.25 times
(d)  0.5 times
Ans 12. (b)

13. 3.2 moles of hydrogen iodide were heated in a sealed bulb at 444°C till the equilibrium was reached. The degree of dissociation of HI at this temperature was found to be 22%. The number of moles of hydrogen iodide present at equilibrium is
(a)  1.87
(b)  2.496                                                       
(c)  4.00
(d)  2.00
Ans 13. (b)

14. The active mass of a reactant is
(a)  Its gram molecular weight
(b)  Its equivalent weight
(c)  Per liter number of moles
(d)  None of these
Ans 14. (c)

15. In a reaction the rate of reaction is proportional to its active mass, this statement is known as
(a)  Law of mass action
(b)  Le- chatelier principle
(c)  Faraday law of electrolysis
(d)  Law of constant proportion
Ans 15. (a)

16. What is the pH of a 0.10 M solution of barium hydroxide, Ba (OH)₂?
(a) 11.31
(b) 11.7
(c) 13.30
(d) None of these
Ans 16. (c)

17. A weak acid HX has the dissociation constant 1 × 10^-5 M. It forms a salt NaX on reaction with alkali. The degree of hydrolysis of 0.1 M solution of NaX is
(a) 0.0001%
(b) 0.01%
(c) 0.1%
(d) 0.15%
Ans 17. (b)

18. The pH of 0.1 M aqueous solution of a weak acid (HA) is 3. What is its degree of dissociation?
(a) 1%
(b) 10%
(c) 50%
(d) 25%
Ans 18. (a)

19. When rain is accompanied by a thunderstorm, the collected rainwater will have a pH value
(a) Slightly higher than that when the thunderstorm is not there.
(b) Uninfluenced by the thunderstorm
(c) Which depends upon the amount of dust in the air
(d) Slightly lower than that of rainwater without a thunderstorm.
Ans 19. (d)

20. CO₂ is
(a) Lewis acid
(b) Lewis base
(d) Bronsted acid
(d) Bronsted base.
Ans 20. (a)

21. The pH of a solution of hydrochloric acid is 4. The molarity of the solution is
(a) 4.0
(b) 0.4
(c) 0.0001
(d) 0.04
Ans 21. (c)

22. When sodium carbonate solution is titrated against the HCl solution, the indicator used is
(a) Phenolphthalein
(b) Methyl orange
(c) Methyl red
(d) Starch.
Ans 22. (b)

23. A buffer solution with a pH of more than 9 can be prepared by mixing
(a) CH₃COONa and CH₃COOH
(b) NaCl and NaOH
(c) NH₄Cl and NaOH
(d) KH₂PO₄ and K₂HPO4
Ans 23. (a)

Que 24. The rate of forwarding reaction is two times that of the reverse reaction at a given temperature and identical concentration, k_{(equilibrium)} is
(a) 0.5
(b) 1.5
(c) 2.5
(d) 2.0
Ans 24. (d)

Que 25. Which of the following aqueous solutions will have the highest pH?
(a) NaCl
(b) CH₃COONa
(c) Na₂CO₃
(d) NH₄Cl
Ans 25. (c)

MCQ Questions for Class 11 Chemistry Chapter 7

Important Questions for CBSE Class 11 Chemistry Chapter – 7  Equilibrium